One common use for containers is the shipment of goods from one location to another. Goods are packed into the container, and a door of the container is closed and latched. Then, the container is transported to a destination by one or more vehicles, such as trucks, planes, trains and/or ships. At the destination, the container door is unlatched and opened, and the goods are removed.
The transportation industry has recognized that it is important to provide security for the goods being transported in such containers. As one aspect of this, there is a need to prevent goods from being removed from a container while it is in transit to its destination, even if the container itself is not stolen, misrouted or misplaced. There is also a need to prevent someone from opening the container and inserting some additional item, such as a bomb.
For this purpose, there are existing seal devices that are used to seal or lock the latch mechanism for the door of the container. The most common type of seal device has a disposable bolt and a reusable housing. The bolt is inserted through the latching mechanism of the container, and the reusable housing is then pressed onto an end of the bolt. The bolt and housing have cooperating structure that completely prevents withdrawal of the end of the bolt from the housing in a direction opposite to its insertion direction. To remove this seal device from a container, the disposable bolt must be cut with a bolt cutter.
Some seal devices of this type also include radio frequency identification (RFID) tag circuitry. If the circuitry detects any form of tampering with the seal device, the circuitry transmits a wireless signal that contains information indicative of the tampering. While seal devices of this type have been generally adequate for their intended purposes, they have not been satisfactory in all respects.